FooD HyGiene & sAFeTy 19
Precise screening for pesticides,
mycotoxins and veterinary drugs
creening of pesticides, mycotoxins a highly complex mixture of 116 pesticides,
High resolution and
and veterinary drugs is of mycotoxins and plant toxins in different
precise mass accuracy is
great importance in regulated concentrations. A 12 min gradient was applied to
a perfect combination
S
environments such as food and a 50 x 2 mm RP C18 column (Thermo Scientific
for food and feed analysis
animal feed analysis. Traditionally these types Hypersil GOLD 1.9 um particles, Thermo Fisher
in complex matrices.
Markus Kellmann, Andreas
of experiments have been carried out using Scientific, Madison, USA) with water/acetonitrile
Wieghaus, Helmut
triple quadrupole instruments. This approach eluents. The method developed was evaluated
Muenster, Lester Taylor
has certain limitations: no post acquisition with respect to sensitivity, selectivity and linearity
and Dipankar Ghosh re-interrogation of data; limited number in standard solutions and extracts from animal
report. of compounds per analysis; cannot screen feed. Mass measurements were performed at
unidentified unknowns. different resolution settings (R = 15 000 and
Because of these limitations, there is currently R = 50 000) to enable comparisons to data
La haute résolution et la
a trend towards full scan MS experiments in acquired by ToF instruments and to demonstrate
précision de la masse est
une combinaison idéale
residue analysis. Current screening approaches the advantage of ultra high resolution. Orbitrap
pour l’analyse des
are performed using high performance ToF detection was carried out using automatic
aliments et des aliments
instruments, with mass accuracies of < 5ppm control of the number of ions entering the
pour bétail dans les
and resolutions of about 15 000, coupled to detector (AGC, target value = 10e6).
matrices complexes. ultra high performance liquid chromatography
Article de Markus
(U-HPLC).
Resolution of Isobaric Pesticides
Kellmann, Andreas
In complex sample matrices (eg food, In cases where isobaric compounds co-elute,
Wieghaus, Helmut
feed, hair, honey) this limited resolution leads erroneous mass accuracy and elemental
Muenster, Lester Taylor et
to inaccurate mass measurements caused by composition assignment will occur if the
Dipankar Ghosh.
unresolved background matrix interferences. In resolving power of the mass spectrometer is
this work a full scan screening approach using insufficient to separate these compounds.
Hohe Auflösung und große a novel single stage Thermo Scientific Orbitrap Fig. 2 shows two pesticides Thiamethoxam
Massepräzision sind eine mass spectrometer coupled to U-HPLC is shown, (C
8
H
10
ClN
5
O
3
S) and Parathion (C
10
H
14
NO
5
PS),
ideale Kombination für
capable of providing high mass accuracy at which have protonated molecular ions (MH
+
)
Lebensmittel- und
resolutions of up to 100 000. Additionally two at 292.02656 and 292.04031, respectively. A
Futteranalysen in
aspects of the analysis will be discussed which resolution higher than 40 000 is needed to
komplexen Matrizen.
Markus Kellmann, Andreas
also greatly benefit from very high resolution: resolve the protontated molecular ion of these
Wieghaus, Helmut
resolving co-eluting, isobaric target compounds; two compounds completely. This is a
☞
Muenster, Lester Taylor
elemental
und Dipankar Ghosh
composition
berichten. determination.
Methods
A new non-hybrid
benchtop LC-MS
Orbitrap mass
spectrometer
(Exactive,
Thermo Fisher
Scientific, Bremen,
Germany) coupled
to a U-HPLC
chromatograph
(Thermo Scientific
Accela, Thermo
Fisher Scientific,
San Jose, USA) was Fig. 1. Schematic of the new Exactive benchtop mass spectrometer, including
used to evaluate HCD collision cell for ‘All Ion Fragmentation’.
www.scientistlive.com
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